Re: [PATCH] ext4: change the type of ext4 cache stats to percpu_counter to improve performance

[Theodore Y. Ts'o]

On Sun, Aug 25, 2019 at 10:28:03AM -0700, Eric Biggers wrote:
> This patch is causing the following.  Probably because there's no calls to
> percpu_counter_destroy() for the new counters?

Yeah, I noticed this from my test runs last night as well.  It looks
like original patch was never tested with CONFIG_HOTPLUG_CPU.

The other problem with this patch is that it initializes
es_stats_cache_hits and es_stats_cache_miesses too late.  They will
get used when the journal inode is loaded.  This is mostly harmless,
but it's also wrong.

I've dropped this patch from the ext4 git tree.

     	     	  	     	      - Ted